Apotex, Inc., and TorPharm, Inc. summary judgment of noninfringement based on use of adjuvants, the Court construes clause (ii) of claim 7 to exclude the eight lactam-promoting adjuvants listed in the specification as those that should be avoided.FN7 In summary,the Court reasoned that while the plain language of the claim does not refer to useable and non-useable adjuvants, the written description and prosecution history require the interpretation of that claim to exclude particular adjuvants listed in the written description as those that should be avoided due to their negative effect on stability of the compounds.
FN7. The Court acknowledges language to the contrary in its October 13, 2004 bench opinion denying Warner-Lambert's application for preliminary injunctive relief directed to Purepac's entry into the market for AB-rated gabapentin capsules. The Court stated that it was inclined, at that time, to agree with Warner- Lambert's claim construction arguments. Now, having had an opportunity to consider the record in more depth, the Court concludes otherwise. Findings of fact and conclusions of law made in the context of a preliminary injunction, let alone observations, do not foreclose conclusions to the contrary at later stages of the litigation. See New Jersey Hosp. Assn. v. Waldman, 73 F.3d, 509, 519 (3d Cir.1995).
2. Comparing Teva's Gabapentin Compositions to Construed Claim-Does Teva Use "Excluded" Adjuvants? Does Teva Use Excluded Substances, But Not as Adjuvants?
Having construed claim 7 to exclude the eight lactam-promoting adjuvants listed as those to be avoided, the Court now turns to comparing Teva's formulation with the construed claim. Teva's position is that its formulations do not infringe the '482 patent because they contain modified maize starch and titanium dioxide, irrespective of the function those substances perform.
In support of its position Teva reasons that the '482 patent is silent on how the lactam-promoting adjuvants function as part of the claimed gabapentin formulation; it instructs only that those adjuvants are to be "avoided." Warner-Lambert responds that the modified maize starch and titanium dioxide are not necessarily relevant to infringement of the '482 patent and, at best, there are disputed issues of material fact with regard to whether the "modified starch" used by Teva in its capsules is the type of "modified maize starch" referred to in the patent as an example of an adjuvant that "should be avoided"; whether the titanium dioxide in Teva's capsule shells and tablet film coatings is being used as an "adjuvant" as that term is used in the '482 patent; and whether the amounts of titanium dioxide used by Teva in its capsule shells and tablet film coatings are sufficient to produce a "material effect on the basic and novel properties" of Warner- Lambert's invention of stable and pure gabapentin compositions.
a. Modified Maize Starch
According to Warner-Lambert, the "pregelatinized" starch used by Teva is not the same as the "modified maize starch" referenced in the '482 patent because the prosecution history indicates that the "modified maize starch" referred to in the patent as reducing gabapentin's stability is in fact "maize starch modified by acid treatment." (Pros.Hist.00320). Warner-Lambert also maintains that a skilled formulator would understand that the "modification" referred to in the patent specification is not pregelatinization because the specification states that sodium starch glycolate-an example of pregelatinized starch-has "no noticeable influence" on the stability of gabapentin.